According to the Associated Press, Wendy's had success testing the app in certain locations, so it will roll out the program to the bulk of its 5,800 restaurants. "If they want to come in and give us business, we want to allow them to pay the way they want to pay," Craig Bahner, chief marketing officer for Wendy's, said in a call.

The only restaurant chain in the big three of the fast-food world that doesn't have a mobile payment option in place is McDonald's. But McDonald's is reportedly working to catch up to Burger King and Wendy's. McDonald's Chief Financial Officer Pete Bensen told the Associated Press, "We're going to have to put some things out there that we know are not 100 percent perfect. But if you wait in this space until everything is 100 percent figured out, then you're going to miss the whole opportunity."

In the coffee world, Starbucks has already proved that mobile payments can succeed. According to the AP, 14 percent of purchases are made on mobile phones via Starbucks' payment app.

Have you tried using your smartphone to pay for your coffee or burger?